The vacuum you need for the distributor, is not manifold vacuum. It's what I believe is called "ported" (I am probably wrong). It comes from a port in the carb, as it advances the timing when the throttle opens, which drops manifold vacuum. If you've got the 97's on there, I suspect the best thing would be to use the full mechanical advance, perhaps dual point mallory. I don't know how the economy and drivability would be, as its a "race" set up.
I'll bet that Edmunds manifold is a real looker!!
